Fundamentals of Post-CMP Cleaning

2007 ◽  
Vol 991 ◽  
Author(s):  
Jin-Goo Park ◽  
Tae-Gon Kim
Keyword(s):  
Adhesion Force ◽  
Critical Factor ◽  
Polished Surface ◽  
Particle Removal ◽  
Particle Adhesion ◽  
Cleaning Process ◽  
Adhesion Forces ◽  
Frictional Forces ◽  
Organic Particles ◽  
Wafer Surfaces

ABSTRACTPost CMP cleaning is necessary for contaminant removal after CMP process. The zeta potential of slurry particle and substrate has been considered to be a critical factor in terms of particle adhesion and removal. The fundamental research such as the calculation and measurement of adhesion forces between slurry particle and wafer surfaces can enhance the understanding of cleaning mechanism and development of cleaning process. The presence of more than two different materials during CMP introduces new defects at the materials interface, corrosion and severe scratches. Device specific chemistry and cleaning process should be introduced and developed for future and current CMP. The highest particle removal efficiency is observed when using cleaning solutions that yields the lowest adhesion force. The effect of frictional and adhesion forces attributed to slurry particles on the quality of Cu surfaces was experimentally investigated during metal CMP process. The magnitude of the adsorption of the organic acid on the slurry particle surfaces can have a significant effect on the frictional behavior as well as the adhesion force. Higher particle adhesion forces resulted in higher friction and might induce defects such as particle contamination and scratches on the polished surface after polishing. The magnitude of particle adhesion force on wafer surfaces in slurries can be directly related to the frictional forces and polished surface quality during CMP process. As low k and poly or bare silicon polishing introduced in fabrication process, the hydrophobicity of these surfaces could affect the defects after polishing. The control of wettability during and after polishing becomes more important in reducing the defects. The organic particles are major defects during metal and poly silicon CMP which may be caused by the surface reaction of organic sources with surfaces.

Frictional behavior and particle adhesion of abrasive particles during Cu CMP

2005 ◽  
Vol 867 ◽  
Author(s):  
Yi-Koan Hong ◽  
Ja-Hyung Han ◽  
Jae-Hoon Song ◽  
Jin-Goo Park
Keyword(s):  
Citric Acid ◽  
Adhesion Force ◽  
Particle Adhesion ◽  
Friction Behavior ◽  
Abrasive Particles ◽  
Frictional Behavior ◽  
Cu Cmp ◽  
Particle Adhesion Force ◽  
Wafer Surfaces ◽  
Citrate Ions

AbstractThe friction behavior and adhesion of abrasive particles were experimentally investigated during Cu CMP process. The highest particle adhesion force was measured in alumina slurry without citric acid. However, the alumina slurry with addition of citric acid had the lowest particle adhesion due to the adsorption of citrate ions on the alumina surfaces. While citrate ions could be easily adsorbed on alumina particles, silica particle showed the least effect on adsorption in citric acid solutions. The magnitude of adsorptions of citrate ions on the particle surfaces had significant effect on frictional behavior as well as adhesion force. Higher particle adhesion force resulted in higher friction, particle contamination and scratches in CMP process. It indicates that the magnitudes of particle adhesions on wafer surfaces in slurries can be directly related to the frictional behavior during CMP process.

Effects of Humidity on Dust Particle Removal during Solar Panel Cleaning

2022 ◽  
Author(s):  
E.Y. Chen ◽  
Peter Renner ◽  
K. Lee ◽  
Bing Guo ◽  
Hong Liang
Keyword(s):  
Relative Humidity ◽  
Dust Particle ◽  
Energy Production ◽  
Adhesion Force ◽  
Solar Panel ◽  
Dust Particles ◽  
Particle Removal ◽  
Adhesion Forces ◽  
Ambient Conditions

Abstract Solar panel cleaning is important to maintain the efficiency of energy production. In this research, we investigated the effects of relative humidity and condensation on the effectiveness of cleaning. The dust particles are subjected to various forces once they are deposited on the surface of a solar panel. When the dust particles continue to build up, they are also subjected to the adhesion forces from the neighboring dust particles. The adhesion forces from the substrates and the neighboring particles are dependent on the ambient conditions. Fundamentally, the interaction between the adhesion force of particle-particle and particle-substrate under various conditions was discussed in this manuscript.

Effect of Wettability of Poly Silicon on CMP Behavior

2007 ◽  
Vol 991 ◽  
Author(s):  
Young-Jae Kang ◽  
Bong-Kyun Kang ◽  
In-Kwon Kim ◽  
Jin-Goo Park ◽  
Yi-Koan Hong ◽  
...  
Keyword(s):  
Adhesion Force ◽  
Surface Wettability ◽  
Cleaning Process ◽  
Solution Ph ◽  
Poly Silicon ◽  
Careful Control ◽  
Polymeric Particle ◽  
Wafer Surfaces ◽  
Si Wafer

ABSTRACTThe hydrophobicity of poly Si is reported to introduce different polishing behavior with careful control of post CMP cleaning process. The purpose of this study was to investigate the effect of poly Si wettability on its CMP behavior. The adhesion force of polymeric particle on the poly Si wafer surfaces was measured in the KOH solution (pH 11) as a function of solution A concentration. Adhesion force decreased and saturated as a function of concentration of solution A. The change of surface wettability affects not only the polishing rates but also the level of contamination on wafer because the interactions between particles and substrates are dependent on the wettability of the surface. Also, hydrophobic poly Si surfaces attracted much more pad particles with water marks than hydrophilic

Mechanism of PVA Brush Loading with Ceria Particles during Post-CMP Cleaning Process

2021 ◽  
Vol 314 ◽  
pp. 259-263
Author(s):  
Samrina Sahir ◽  
Hwi Won Cho ◽  
Nagendra Prasad Yerriboina ◽  
Tae Gon Kim ◽  
Satomi Hamada ◽  
...  
Keyword(s):  
Electrostatic Attraction ◽  
Particle Removal ◽  
Cross Contamination ◽  
Cleaning Process ◽  
Particle Loading ◽  
Cleaning Efficiency ◽  
Solution Ph ◽  
Cleaning Solution ◽  
Oppositely Charged ◽  
Process Interaction

Brush scrubbing is a well-known post CMP cleaning process. Interaction between PVA brush and the particles removed during the process must be considered while designing a cleaning process. In this work, the effect of cleaning solution pH was investigated in terms of particle removal from the wafer and subsequent loading to the PVA brush nodule. Higher cleaning of particles from wafer was observed for pH 2 and 12 cleaning solutions and poor cleaning for pH 7 cleaning solution. In contrast, the brushes were loaded heavily for pH 7 compared to pH 2 and 12. Higher electrostatic attraction between oppositely charged PVA and ceria surfaces provided higher ceria particles loading to PVA brush in acidic and neutral cleaning solutions. This particle loading to PVA brush can further effect cleaning efficiency as well as cross-contamination.

scholarly journals Carbohydrate–carbohydrate interaction provides adhesion force and specificity for cellular recognition

2004 ◽  
Vol 165 (4) ◽  
pp. 529-537 ◽  
Author(s):  
Iwona Bucior ◽  
Simon Scheuring ◽  
Andreas Engel ◽  
Max M. Burger
Keyword(s):  
Adhesion Force ◽  
Species Specificity ◽  
Live Cells ◽  
Sponge Cell ◽  
Cell Recognition ◽  
Adhesion Forces ◽  
Cellular Recognition ◽  
Strong Adhesion ◽  
Species Specific ◽  
Cell Cell

The adhesion force and specificity in the first experimental evidence for cell–cell recognition in the animal kingdom were assigned to marine sponge cell surface proteoglycans. However, the question whether the specificity resided in a protein or carbohydrate moiety could not yet be resolved. Here, the strength and species specificity of cell–cell recognition could be assigned to a direct carbohydrate–carbohydrate interaction. Atomic force microscopy measurements revealed equally strong adhesion forces between glycan molecules (190–310 piconewtons) as between proteins in antibody–antigen interactions (244 piconewtons). Quantitative measurements of adhesion forces between glycans from identical species versus glycans from different species confirmed the species specificity of the interaction. Glycan-coated beads aggregated according to their species of origin, i.e., the same way as live sponge cells did. Live cells also demonstrated species selective binding to glycans coated on surfaces. These findings confirm for the first time the existence of relatively strong and species-specific recognition between surface glycans, a process that may have significant implications in cellular recognition.

Adhesion and Removal of Alumina Slurry Particles on Wafer Surfaces in Cu CMP

2005 ◽  
Vol 103-104 ◽  
pp. 275-278
Author(s):  
Yi Koan Hong ◽  
Ja Hyung Han ◽  
Jin Hyung Lee ◽  
Jin Goo Park ◽  
Ahmed A. Busnaina
Keyword(s):  
Alumina Particle ◽  
Adhesion Force ◽  
Interaction Force ◽  
Zeta Potentials ◽  
Alumina Particles ◽  
Particle Contamination ◽  
Cu Cmp ◽  
Wafer Surfaces

The adhesion force and removal of alumina particles on Cu, Ta, TEOS, SILKTM, Aurora and FSG wafer surfaces were experimentally and theoretically investigated in slurry solutions of different pHs. These wafer surfaces showed negative zeta potentials in the investigated pH ranges with exception of FSG and Ta. However, the zeta potentials of FSG surface drastically decreased with increasing pH. The lowest adhesion force and smallest number of alumina particles were measured between alumina particle and FSG surface in a slurry solution of pH 11. Alkaline slurry was much more desirable in controlling the level of particle contamination during Cu CMP. The pH of the slurry and zeta potentials of the surfaces played important roles in controlling the interaction force.

Capillary Forces Described by Effective Contact Angle Distributions via Simulations of the Centrifuge Technique

MRS Advances ◽  
2016 ◽  
Vol 1 (31) ◽  
pp. 2237-2245
Author(s):  
Myles Thomas ◽  
Elizabeth Krenek ◽  
Stephen Beaudoin
Keyword(s):  
Surface Roughness ◽  
Contact Angle ◽  
Smooth Surface ◽  
Adhesion Force ◽  
Capillary Forces ◽  
Angle Distribution ◽  
Particle Adhesion ◽  
Multiple Factors ◽  
Effective Contact ◽  
Condensed Moisture

ABSTRACTUnderstanding particle adhesion is vital to any industry where particulate systems are involved. There are multiple factors that affect the strength of the adhesion force, including the physical properties of the interacting materials and the system conditions. Surface roughness on the particles and the surfaces to which they adhere, including roughness at the nanoscale, is critically important to the adhesion force. The focus of this work is on the capillary force that dominates the adhesion whenever condensed moisture is present. Theoretical capillary forces were calculated for smooth particles adhered to smooth and rough surfaces. Simulations of the classical centrifuge technique used to describe particle adhesion to surfaces were performed based on these forces. A model was developed to describe the adhesion of the particles to the rough surface in terms of the adhesion to a smooth surface and an ‘effective’ contact angle distribution.

Friction Characteristics and Adhesion Force Under Low Normal Load

1995 ◽  
Vol 117 (4) ◽  
pp. 569-574 ◽  
Author(s):  
Yasuhisa Ando ◽  
Yuichi Ishikawa ◽  
Tokio Kitahara
Keyword(s):  
Friction Coefficient ◽  
Friction Force ◽  
Adhesion Force ◽  
Normal Load ◽  
Adhesion Forces ◽  
Test Pieces ◽  
Before And After ◽  
Constant Normal Load ◽  
The Mean ◽  
Steel Balls

The friction coefficient and adhesion force between steel balls and flat test pieces were measured during friction under low normal load in order to examine the tribological characteristics. First, the friction coefficients were measured under a constant normal load of 0.8 to 2350 μN, and the adhesion forces were measured before and after each friction. The result showed that the friction coefficient was highest at low normal loads, while the friction force divided by the sum of the normal load and the mean adhesion force was almost constant over the whole range of loads. Second, when the normal load was reduced gradually during friction, friction still acted when the normal load became negative and a pulling off force was applied to the surface. Thus an adhesion force acts during friction and this adhesion force affects the friction force in the same way as the normal load.

scholarly journals Adhesion force mapping on wood by atomic force microscopy: influence of surface roughness and tip geometry

2016 ◽  
Vol 3 (10) ◽  
pp. 160248 ◽  
Author(s):  
X. Jin ◽  
B. Kasal
Keyword(s):  
Surface Roughness ◽  
Atomic Force Microscopy ◽  
Wood Surface ◽  
Adhesion Force ◽  
Data Interpretation ◽  
Natural Fibre ◽  
Force Distribution ◽  
Adhesion Forces ◽  
Force Microscopy ◽  
Atomic Force

This study attempts to address the interpretation of atomic force microscopy (AFM) adhesion force measurements conducted on the heterogeneous rough surface of wood and natural fibre materials. The influences of wood surface roughness, tip geometry and wear on the adhesion force distribution are examined by cyclic measurements conducted on wood surface under dry inert conditions. It was found that both the variation of tip and surface roughness of wood can widen the distribution of adhesion forces, which are essential for data interpretation. When a common Si AFM tip with nanometre size is used, the influence of tip wear can be significant. Therefore, control experiments should take the sequence of measurements into consideration, e.g. repeated experiments with used tip. In comparison, colloidal tips provide highly reproducible results. Similar average values but different distributions are shown for the adhesion measured on two major components of wood surface (cell wall and lumen). Evidence supports the hypothesis that the difference of the adhesion force distribution on these two locations was mainly induced by their surface roughness.

Determination of Adhesion Forces Between Smooth and Structured Solids

2012 ◽  
Author(s):  
Hartmut R. Fischer ◽  
Edwin R. M. Gelinck
Keyword(s):  
Adhesion Force ◽  
Smooth Surfaces ◽  
Adhesion Forces ◽  
Real Area Of Contact ◽  
Study Results ◽  
Colloidal Probes ◽  
Good Agreement ◽  
Real Area

The tendency of smooth surfaces to stick spontaneously to each other is becoming a serious problem, with: a) the increasing quality in surface finish for many components and systems, b) on miniaturization in mechanical components, and c) in demanded precision of positioning of parts in high-end equipment machines and systems. Surfaces tend to be made smoother in order to gain flatness or in order to fulfill the need for more precise and reproducible positioning of parts. Adhesion or even sticking of the surfaces is a major showstopper for these applications. There are several measures that can be taken in order to reduce spontaneous adhesion. Quantification of the effectiveness of the chosen solution is most often done using an AFM with probes varying from 1 nm to 8 micron of contact diameter. A serious disadvantage in measuring adhesion by sharp tips is the wear of the tips. Sharp tips wear easily, resulting in undefined contact areas. When the real area of contact is not well defined, the quantification of the adhesion force is not significant. In the current study results of AFM measurements from literature with different tip diameters of colloidal probes are compared with measurements we performed using AFM cantilevers with a plateau tip and using probes from large spheres using an alternative setup (UNAT). These methods give results that are in good agreement with values found in literature. Large contacting surface enhance the quality of the measured adhesion values. Another part of the study deals with a deliberately roughening of smooth surfaces to minimize (spontaneous) adhesion. Good agreement has been found with existing results. For the use of larger surfaces it is important that the surfaces to be tested are extremely clean. Particles on smooth surface do influence the measurements quite easily. Especially for larger areas, the possibility of encountering particles on the surface are more likely, when particles are present. For the measurements in this study a lot of care has been taken therefore to remove contamination: particles as well as contamination of organic origin.

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